1. Field of the Invention
Example embodiments generally relate to an image scanner, an image forming apparatus, and/or an image scanning method, for example for scanning an image.
2. Description of the Related Art
A related-art image forming apparatus, such as a copying machine, a facsimile machine, a printer, or a multifunction printer having two or more of copying, printing, scanning, and facsimile functions, forms an image on a recording medium (e.g., a sheet) according to image data.
The image forming apparatus generally includes an image scanner for scanning an image on an original to create image data. For example, in the image scanner, a lamp emits light onto an original bearing an image. The light reflected by the original enters a light receiver including a photoelectric conversion device (e.g., a charge-coupled device).
FIGS. 1 and 2 illustrate an example related-art image scanner 100R. In the image scanner 100R, lamps 11R are mounted on a first carriage 10R. The first carriage 10R moves in a main scanning direction. While the lamps 11R mounted on the first carriage 10R move, the lamps 11R emit light onto an original placed on an exposure glass. The lamps 11R may emit light onto a large size original. Therefore, the first carriage 10R moves from a position corresponding to an end of the exposure glass to a position corresponding to another end of the exposure glass in the main scanning direction.
A first mirror 13R, a second mirror 21R, and a third mirror 22R deflect light reflected by the original toward a light receiver (not shown). The first mirror 13R is mounted on the first carriage 10R. The second mirror 21R and the third mirror 22R are mounted on a second carriage 20R. The second carriage 20R moves with the first carriage 10R at a half speed of the first carriage 10R, so as to maintain a constant optical light path length originating from the original and terminating at the light receiver even when the lamps 11R emit light onto the original from various positions. Thus, the first mirror 13R deflects light reflected by the original toward the second mirror 21R. The second mirror 21R deflects the light toward the third mirror 22R. The third mirror 22R deflects the light toward the light receiver.
A power source 120R for driving the lamps 11R is connected to the lamps 11R via a flexible circuit board 110R serving as a power supplier. The flexible circuit board 110R has flexibility to cause the first carriage 10R to move smoothly. The flexible circuit board 110R extends from the power source 120R to the lamps 11. For example, the flexible circuit board 110R runs on a bottom of a body 101R, passes the second carriage 20R, and reaches the lamps 11R. The second carriage 20R turns the flexible circuit board 110R toward the first carriage 10R.
The flexible circuit board 110R may sag due to its weight. When the first carriage 10R is far removed from the second carriage 20R, the flexible circuit board 110R may sag substantially, and may block an optical light path P formed between the first mirror 13R and the second mirror 21R, resulting in formation of a faulty image. For example, when the first carriage 10R is near the second carriage 20R, the flexible circuit board 110R may not sag substantially, as illustrated in FIG. 1. However, when the first carriage 10R is far removed from the second carriage 20R in order to scan a large size original, the flexible circuit board 110R may sag substantially and may block the optical light path P, as illustrated for example in FIG. 2.
To address this problem, another example of a related-art image scanner includes an elastic portion for applying tension to the flexible circuit board 10R. The elastic portion increases tension on the flexible circuit board 110R as a distance between the first carriage 10R and the second carriage 20R increases. Resistance is applied to an edge of the flexible circuit board 110R in particular, and such locally applied resistance may degrade the durability of the flexible circuit board 110R, resulting in broken circuits and sharply reducing reliability.